26 documents found, page 1 of 3
Self-supporting hyaluronic acid-functionalized G-quadruplex-based perfusable mu...
Sousa, Vera; Amaral, Adérito J. R.; Castanheira, Edgar J.; Marques, Igor; Rodrigues, João M. M.; Félix, Vítor; Borges, João; Mano, João F.Dynamic G-quadruplex supramolecular hydrogels have aroused great interest in a broad range of bioapplications. However, neither the development of native extracellular matrix (ECM)-derived natural biopolymer-functionalized G-quadruplex hydrogels nor their use to create perfusable self-supporting hydrogels has been explored to date, despite their intrinsic potential as carrier vehicles of therapeutic agents, or ...
Being positive is not everything: experimental and computational studies on the...
Zubi, Ahmed; Alnafisah, Hawazin A.; Turega, Simon; Marques, Igor; Gomes, José R. B.; Thomas, Jim A.; Félix, VítorThe interaction of the self-assembled trinuclear ruthenium bowl 13+ , that displays three other accessible oxidation states, with oxo-anions is investigated. Using a combination of NMR and electrochemical experimental data, estimates of the binding affinities of 14+ , 15+ , and 16+ for both halide and oxo-anions were derived. This analysis revealed that, across the range of oxidation states of the host, both hi...
Selective potassium chloride recognition, sensing, extraction, and transport us...
Docker, Andrew; Marques, Igor; Kuhn, Heike; Zhang, Zongyao; Félix, Vítor; Beer, Paul D.Chalcogen bonding (ChB) is rapidly rising to prominence in supramolecular chemistry as a powerful sigma (σ)-hole-based noncovalent interaction, especially for applications in the field of molecular recognition. Recent studies have demonstrated ChB donor strength and potency to be remarkably sensitive to local electronic environments, including redox-switchable on/off anion binding and sensing capability. Influe...
Binding and transport properties of a benzo[b]thiophene‐based mono‐(thio)urea l...
Moiteiro, Cristina; Marques, Igor; Ryder, William G.; Cachatra, Vasco; Carvalho, Sílvia; Chen, Li‐Jun; Goodfellow, Brian J.; Gale, Philip A.Using the chemical versatility of the benzo[b]thiophene motif, an extensive library of 24 (thio)urea receptors, with different binding properties and lipophilicities, was prepared and included α,α-, α,β-, β,β-, β,γ-, α,γ-, and γ,γ-benzo[b]thiophene positional isomers, as well as β- or γ-benzo[b]thiophene-based molecules decorated with aliphatic chains or aryl moieties with different fluorination degrees. 1H NMR...
Hydrosulfide (HS⁻) recognition and sensing in water by halogen bonding hosts
Mitchell, Edward J.; Beecroft, Adam J.; Martin, Jonathan; Thompson, Sally; Marques, Igor; Félix, Vítor; Beer, Paul D.Hydrogen sulfide (H₂S) plays a crucial signalling role in a variety of physiological systems, existing as the hydrosulfide anion (HS⁻) at physiological pH. Combining the potency of halogen bonding (XB) for anion recognition in water with coumarin fluorophore incorporation in acyclic host structural design, the first XB receptors to bind and, more importantly, sense the hydrosulfide anion in pure water in a reve...
Hydrazones in anion transporters: the detrimental effect of a second binding site
Martínez-Crespo, Luis; Halgreen, Lau; Soares, Márcio; Marques, Igor; Félix, Vítor; Valkenier, HennieSynthetic anion transporters can be developed using anion receptors that are able to bind the anion and stabilize it in the lipophilic interior of a bilayer membrane, and they usually contain functional groups with acidic NHs, such as ureas, thioureas and squaramides. To assess the suitability of acylhydrazones as a new functional group for the preparation of anion transporters, we have studied a family of thio...
Estrogen receptors in urogenital schistosomiasis and bladder cancer: Estrogen r...
Bernardo, Carina; Santos, Júlio; Costa, Céu; Tavares, Ana; Amaro, Teresina; Marques, Igor; Gouveia, Maria João; Félix, Vítor; Afreixo, VeraEstrogen-like metabolites have been identified in S. haematobium, the helminth parasite that causes urogenital schistosomiasis (UGS) and in patients´ blood and urine during UGS. Estrogen receptor (ER) activation is enriched in the luminal molecular subtype bladder cancer (BlaCa). To date, the significance of ER to these diseases remains elusive. We evaluated ERα and ERβ expression in UGS-related BlaCa (n = 27),...
Estrogen receptors in urogenital schistosomiasis and bladder cancer: estrogen r...
Bernardo, Carina; Santos, Júlio; Costa, Céu; Tavares, Ana; Amaro, Teresina; Marques, Igor; Gouveia, Maria João; Félix, Vítor; Afreixo, VeraEstrogen-like metabolites have been identified in S. haematobium, the helminth parasite that causes urogenital schistosomiasis (UGS) and in patients´ blood and urine during UGS. Estrogen receptor (ER) activation is enriched in the luminal molecular subtype bladder cancer (BlaCa). To date, the significance of ER to these diseases remains elusive. We evaluated ERα and ERβ expression in UGS-related BlaCa (n = 27),...
Unprecedented Double aza-Michael Addition within a Sapphyrin Core
Figueira, Flavio; Marques, Igor; Farinha, Andreia S. F.; Tome, Augusto C.; Cavaleiro, Jose A. S.; Silva, Artur M. S.; Sessler, Jonathan; Felix, VitorA novel sapphyrin derivative was obtained from the reaction between a free-base sapphyrin and dimethyl acetylenedicarboxylate (DMAD). The formation of the new compound involved a double aza-Michael addition of two pyrrolic NH groups to a DMAD molecule, with the formation of a disubstituted ethano bridge. The NMR spectral data reveal a product with an unsymmetrical structure; DFT calculations provided support fo...
Tilting and Tumbling in Transmembrane Anion Carriers: Activity Tuning through n...
Edwards, Sophie J.; Marques, Igor; Dias, Christopher M.; Tromans, Robert A.; Lees, Nicholas R.; Felix, Vitor; Valkenier, Hennie; Davis, Anthony P.Anion transport by synthetic carriers (anionophores) holds promise for medical applications, especially the treatment of cystic fibrosis. Among the factors which determine carrier activity, the size and disposition of alkyl groups is proving remarkably important. Herein we describe a series of dithioureidodecalin anionophores, in which alkyl substituents on one face are varied from C-0 to C-10 in two-carbon ste...